Bad Cat High Plate Voltage and Cathode Current

[Bwmitc9285]

I recently bought a Bad Cat Luca and when I got it I noticed some of the tubes were microphonic. While I had the chassis out to change the tubes I checked the voltages and noticed that the EL34s had a plate voltage of 420 and a voltage drop of 23V across a 270 ohm cathode resistor which means each tube is running around 32 watts (81 mA). This seems way to high. Aside from changing the rectifier (GZ34) I have a few ideas of how to address these issues but wanted to see what you all think is the best solution. Thanks for your assistance!

[pdf64]

What is the amp's intended mains Vac, and its actual, measured mains Vac, and its actual, measured heater voltage (eg 6.3Vac), from the power transformer (at idle)?

[sluckey]

Are the two EL34s sharing a single cathode resistor? If so, my math says both tubes together are running at 33.8 watts. Assuming they are perfectly matched, each tube would be running at half that, or 17 watts. I'm neglecting screen current so the actual plate dissipation will be a bit lower than that.

[Bwmitc9285]

I should have clarified. Each tube has a 270 ohm cathode resistor.

[shooter]

this data sheet seems to say you're close enough 

[Bwmitc9285]

Finally had a moment to measure the secondary voltages. I’m getting 351 Vac with the schematic showing 321 Vac. Heaters are reading 6.3 v.